Automatic clutch for fluid-operated hoists



(No Model.)

I'. MARIS. AUTOMATIC CLUTCH TCR FLUID CPERATEU HCISTS.

No. 579,88/5. Patented Mar. 30, 1897.

we cams PETERS co vamo L wo FRANK MARIS, OF PHILADELPHIA, PENNSYLVANIA.

AUTOMATIC CLUTCH FOR FLUlD-OPERATED HOISTS.

SPECIFICATION forming part of Letters Patent No. 579,885, dated March 30, 1897.

Application filed May 28, 1896.

To @ZZ whom, it may concern,.-

Be it known that I, FRANK MARIS, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Automatic Clutches for Fluid- Operated Hoists, of which the following is a specification.

My invention relates to that class of hoisting apparatus .in which motive fluid is admitted to a cylinder and caused to act upon a piston capable of traveling therein, said piston being connected to a rod to which the load is hung.

My invention consists of a clutch adapted to engage with the piston-rod or other movable portion of the hoist which supports the load, said clutch being connected to the valve which supplies the motive fluid to the cylinder,whereby said valve will be opened to supply motive fluid to the cylinder should the load lower accidentally or will be opened. to exhaust motive fluid from the cylinder should there be any tendency of the load to raise by reason of expansion of the fluid in the cylinder.

My invention is fully illustrated in the accompan ying drawings, in which Figure l is a side elevation illustrating my invention as applied to an air-hoist having a vertically-moving piston. Fig. 2 is a section on the line 2 2, Fig. l. Fig. 3 is a plan view of a traveling` hoist provided With a horizontally-moving piston-rod which operates a chain for lifting the load, this view showing a modified form of my invention. Figs. 4 and 5 are respectively enlarged plan and end views of the device shown in Fig. 3, and Figs. G, 7, S, and 9 are views illustrating further modications of my invention.

In Fig. l, A is the cylinder of the hoist; B, the piston-rod;` C, the chest containing the governing-valve, and D the pipe for conveying motive fluid to the cylinder. Surrounding the piston-rod B is a friction-collar B', held in contact therewith by means of a friction-block, as b, and a suitable adjustingscrew b', Fig. 2, a spring b2 being preferably interposed between the friction-block and the adj Listing-screw. The valve in the chest C may be any ordinary form of three-way valve, and it is provided with a two-armed lever C',

Serial No. 592,735. (No model.)

whereby the valve may be moved either to the inlet, cut-off, or exhaust position, as may be desired, suitable operating-chains c c being connected to the lever, as shown in Fig. l. By inlet position I mean that adjustment of the valve which provides for a ilow of motive fluid into the cylinder, by cut-off7 position that adjustment which cuts off either inlet or escape of motive fluid, and by eX- haust position that adjustment which provides for the ilow of motive vfluid from the cylinder through the valve and its chest to the air.

Hung to studs d on the side of the friction-collar B is a yoke-lever a', carried by a bracket awhich is suspended from the valvechest C. Connecting the yoke-arm a with the lever C'is a link cwhich serves to transmit to the lever C any movement of the piston-rod which is transmitted to the frictioncollar B.

In Fig. 3 I have shown the clutch in the form of a yoke-lever e, having a sprin g-pressed arm e', the two arms of the yoke being adapted to engage a sheave, such as E, around which the chain f, carrying the load, passes. The chain in this instance is connected to the piston-rod B2 of a horizontal cylinder, passes around the sheaves E and E', over the sheave F, through the hoisting-block, and over the sheave F', carried by the trolley G, and is connected at the rear of the hoistlat a point not shown in the drawings. The yoke-lever e is pivoted at c2 to the frame of the hoist and is connected at its outer end to the rod e3, which operates the lever G2, controlling the valve in the chest C3.

In Figs. 6, 7, 8, and 9 I have shown modified forms of' clutches of the general style shown in Figs. 3, 4, and 5. In Figs. 6 and 7, H represents an auxiliary friction-wheel carried by the shaft or spindle of asheave, as E, friction-plates h and h flanking this frictionwheel, and annular wooden strips h2 being interposed between the plates and the wheel for better frictional contact. The plate h is provided with an arm h3, connected to the rod which operates the lever controlling the supply-valve. In Figs. 8 and 9 a two-part springpressed band-brake is shown adapted to a flan @ed sheave carried as in the forms shown IOO in Figs. G and '7, by the spindle of a sheave, as E, one part et the brake having an arm connected to the rod which operates the valve.

My invention is particularly adapted for arresting the accidental lowering of a load supported by any motive-fluid hoist, such lowering, for instance, as would be due to any leakage from the cylinder.

The operation of the device is as follows: The hoist in Fig. l is shown with the liook in the raised position at the point where the load is to be supported, the valve in the chest C having been closed by pulling down on the chain c of the lever C. The admission of motive iiuid to the cylinder is thereby cut off, and the load is held by the motive iluid admitted beneath the piston. "While the hoisting operation was in progress, the pistonrod slipped through the friction-collar, as the latter could not move with it, being held in position owiii g toits connection with the lever C', which was held in position by the attendant; but should the piston after the closing of the valve descend from any cause it will carry the frictioirblock with it, and the downward movement of the friction-block will be imparted to the yoke-lever a', and thence to the lever C, through the medium of the link c`-, thereby raising said lever and opening the valve in the chest C for the admission of motive `fluid to the cylinder. As the piston rises tlie friction-block iiioves with it and operates the lever C, so as to close the valve again by the time the load has been lifted to the proper height. It is obvious also that any accidciital movement of the piston in an upward direction, such as might be caused by expansion in the cylinder oi by a reduction of weight on the rod, will carry the frictioircollar with it, and this movement imparted to the lever C' will cause the valve to open to the exhaust and allow a certain quantity of the motive iluid contained within the cylin der to escape, so as to bring the load back to its original position. Thus it will be seen the lead is constantly kept in a state of coniplete equilibrium.

In all eases the frictional connection is such that it will slip on the moving part when and so long as the lever C is held in position by hand, but when said lever is released after adjustment to the cut-oft position it is then under control of the friction device and any movement oi the latter in one direction or the other is imparted to said lever.

I claim as my inventioiil. The combination in a fluid actuated hoist, of the hoisting-cylinder, its pistoii-rod, a valve controlling the flow of motive fluid into the cylinder, a friction-clutch constantly in operative engagement with a movable por tion of the hoist, and a connection between said clutch and the valve, whereby the latter will be automatically opened by accidental or unintentional movement of the hoist, substa-ntially as specified.

2. The combination in a ilu id actuated hoist, of the lioisting-cylinder, its piston-rod, a valve controlling the ilow of motive fluid into and from the cylinder, a friction-clutch constantly in operative engagement with a movable portion of the hoist, and a connection between said clutch and the valve,where by the latter will be automatically operated by accidental or unintentional movement of the hoist in either direction, substantially as specified.

3. The combination in a iluid actuated hoist, of the hoisting-cylinder, its piston-rod, a valve controlling the flow oi' motive fluid into the cylinder, a friction-clutch in engagement with the piston-rod, and a connection between said clutch and the valve, whereby the latter will. be automatically opened by accidental or unintentional movement of the hoist, substantially as specified. i

li. rlhe combination in a iluid actuated hoist, ot' the hoisting-eylinder7 its piston-rod, a valve controlling the admission of motive iluid to the cylinder, a friction clutch or collar encircling the piston-rod, a lever carrying said clutch, a two-armed lever for operating the iluid-supply valve, and a link connecting the friction-clutch lever with the lever con trolling the valve, substantially as described.

5. The combination in a iluid operated hoist, of the hoisting-cylinder, its piston-rod, a valve controlling the ilow of motive iluid to the cylinder, a collar encircling the pistonrod and in frictional contact with the same, said collar liaviiiga contact-piece held against the pistonr0d by a spring and a suitable adjusting-screw, and a connection between the frictioiicollar and the fluid-supply valve, whereby said valve will be opened when the piston-rod is accidentally moved, substantially as described.

In testimony whereof I have signed my naine to this specification in the presence ot two subscribing witnesses.

FRANK MARIS.

Witnesses:

MURRAY C. llovnn, Jos. ll. KLEIN.

IOO 

